Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
WO 94/27489 ~ ~ ~ ~ ~ ' PCT/US94/03498
LOW PRODUCT ALARM ~'OR SOLID PRODUCTS
Field of the Invention
The present invention relates generally to
dispensers for solid products such as detergents, rinse
agents, or the like; and more particularly to a
dispenser of the type which creates a concentrated
solution by applying a diluent to a solid product, and
which includes a low product alarm for detecting and
providing an indicia that replenishment of the solid
product is required.
Backcrround of the Invention
A number of differing techniques have been developed
and utilized for converting a solid cleaning composition
into a concentrated cleaning solution. Examples of such
cleaning solutions include detergents, rinse agents, and
the like. One such employed technique uses a solid
block-type cleaning composition which is placed (and
thereby contained) within an enclosure. The solid block
is dissolved by the impingement of a diluent upon the
solid block. A common diluent is water. Use of this
method typically dissolves only a portion of the solid
block with each cycle. The resulting concentrated
cleaning solution formed by the action of the water
falls due to gravity into an underlying reservoir, or is
directed by a conduit to the utilization point.
Those skilled in the art will appreciate that the
utilization of solid cleaning compositions has several
advantages over the use of pre-mixed liquid cleaning
compositions. These advantages include that solid
compositions are easier and more cost effective to ship
due to its greatly-reduced weight; the solid composition
requires less storage space; and the solid composition
allows for a safer work environment by reducing possible
splashing of hazardous chemicals. Additionally, the
solid composition is more convenient for the user, and
it permits easy transfer from a container to a dispenser
-- involving no pouring, spilling or leftover product.
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A problem, however, has been encountered in the past
with the foregoing dispensers. More specifically, the
required and/or desired concentration of the resulting
cleaning solution is maintained only as long as a
minimum amount of the solid block of product is present
in the dispenser prior to the activation of each cycle.
When the solid block reaches a low level condition, then
the resulting cleaning solution falls from the desired
concentration. In one type of application, it has been
empirically found that up to 200 to 300 cycles are
required to reestablish the desired concentration after
a low product cycle has occurred. Accordingly, there is
a need to detect a low product condition level and to
provide an indication of such a condition.
Despite this need, it is believed that product
alarms for solid product dispensers of this type have
not been utilized in the past. In other types of
dispenser devices, however, measurements have been made
of the resulting solution -- one example being measuring
the conductivity of an alkaline solution using
conductivity cells. In this latter type of device, as
the alkalinity decreases, the alarm sounds. Though in
order to reestablish the desired concentration, the
change in conductivity may occur too late in the cycle
to maintain a desired constant solution concentration.
Additionally, such conductivity cells are expensive and
cannot be used if the solution is not conductive.
Other known types of alarms have attempted to
measure colors of resulting solutions. However, color
does not always produce accurate results due to
wavelength variations, and so the results of such alarms
have been unsatisfactory. Other devices such as
thermistors, conductivity sensors, pressure sensors,
vacuum, floats, and piezoelectric cells have also been
attempted to be utilized in alarm devices. However,
each of the foregoing has had drawbacks, and is not
appropriate to the present type of dispenser since it
2158027_ ....
does not directly measure the ph~rsical element which is
of interest -- namely the solid composition which needs
periodic replenishing.
~.;ne reference, German Patent 32 40 04; A_ discloses
S usi ng ar_ optoel et tri cal sensor to detect whether a
granular laundry car dishwashing deterger_t is present
within a dishwashing machine. In these t_.~es of
devices, the active agent =s placed in metered portions
each time prior to the machine being turned on.
Accordir_gly, the indicia merely provides an indication
of whether the agent was loaded or was not loaded. The
indicia does not provide an indication that
replenishmer_t is necessary or_or to actually depleting
the entire source of agent.
=uropean Patent ~P-A-0 S33 238 generally discloses a
device for impinging a stream of diluent Into a
deterger_t supply pack.
T~~ Y T O PYe ~ r o r ' o
_ e_e~.Or.., th.._ ar=seS ~ e~d for a den=c.. and
met~_od in a solid to 1 i~.:id dispenser for deserting a
low product level, and prompting a user o _eplenish the
solid product by providing indicia of the low product
level, preferably prior to adverse impacts on the
solution concentration.
2S Summary of the Invention
The present invention provides a simple, relatively
inexpensive and yet reliable method and apparatus for
automatically and continuously sensing the level of
solid product in a solid composition to concentrated
solution dispenser. Once a low level conditior_ is
detected, a sensor circuit triggers one or more
perceptible indicia that a low level condition exists.
The detector is arranged and configured to detect a low
level condition prior to such condition adversely
3S affecting the solution concentration. Therefore, enough
product remains in the dispenser to maintain the desired
concentration of solution for a predetermined number of
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~a
cycles at the time that the perceptible indicia is
activated.
In a preferred eItlbOdlment cons~r~lCted aCCOrC,L''i_ng t0
the principles of the present invention, the low level
detector utilizes a sensor comprised of ar_ =nfrared
e~nit-er and receiver to project a beam of light ac=oss a
cavityienclosure which contains t:ze solid product. rnThen
the product reaches a level at which more solid product
should be added, an alarm indicia means is triggered.
The alarm indicia means is comprised of an audible horn
and a visually perceptible light.
The preferred dispenser device in which the sow
product alarm is utilized comprises ar_ apparatus for
dispensing a wash chemical solution which has peen
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created by dissolving a solid wash chemical in a
diluent. The dispenser includes a sump which is
positioned beneath an outlet port for the wash chemical
solution. The sump collects the dissolved wash
chemical. The sump is contained within a reservoir,
whereby overflow of the wash chemical from the sump is
collected within the reservoir. A pick-up tube is
positioned to withdraw the wash chemical solution from
the reservoir and transport it to the utilization point.
Preferably, a screen is provided above the sump for
filtering unwanted particulates.
One advantage of the present invention is the
elimination or substantial reduction of concentration
variances within the reservoir. It has been determined
that the present invention reduces such variations,
since a minimum amount of the solid chemical composition
will be located within the dispenser before the low
product alarm is activated. This reduction in
concentration variations results in a cleaning solution
which has a more consistent concentration.
Several advantages flow from eliminating variations
in the concentration. First, the likelihood that pumps,
or other flow control devices become clogged is reduced.
Second, if the concentration is too low, the
effectiveness of the chemical solutions at the
utilization point is removed. Thus, by providing for
consistent dispensing of the proper concentration,
product waste is minimized while the efficiency is
maximized. Accordingly, the cleaning product can be
used to its optimum capabilities.
Another advantage of the present invention is its
simplicity of construction and ease of manufacture. The
present invention is relatively low in cost, and is
modular in construction so that the entire assembly may
be retrofitted within existing devices.
Yet another advantage is that the solid chemicals
which may attach to the sides of the solid product
21580~7-
S
enclosure area do not normally interfere with the
operation of the low product alarm. However, the bioc:c
of solid chemicals does provide an opaque screen to the
light from, the emitter to the sensor (i.e., the sensor
remains turned of= ur_ti1 1 fight stri.~ces it) such that t he
presence of the desired andior predetermined amount of
solid chemical causes the device to operate in its
intended manner.
Therefore, according to one aspect of the invention,
i0 there is provided a dispenser of the type which forms
and dispenses a solution, the solution formed by
dissolving a solid wash chemical in a diluent,
comprising: a) a container for holding a predetermined
amount of a solid wash chemical; b) diluent application
S means for impinging a diluent onto the solid wash
chemical within said container, wherein a solution is
formed for subseauent use by a utilization vehicle; c
solution col_ectien means for collecting said solutior_;
d) light detector means operatively located proximate
2G said container, said detector means including: ) an
emitter for emitting a beam of light through said
container, whereby the beam of light is bloc:c=d by the
solid wash chemical when at least a predeterm_ned
approximate amount. of the solid wash chemical is prose~~
~S in said container; and ii) a receiver for receivinc the
beam of light from said emitter and automatically
determining when the solid wash chemical needs
replenishment based on whether the beam of licht reaches
said receiver; and e) wherein said emitter and receiver
30 are arranged and configured such that when less than
said predetermined approximate amount of the solid wash
chemical remains in the dispenser, said perceptible
indicia are triggered, whereby an operator is alerted to
replenish the supply of the solid wash chemical before
3S the supply of the solid wash chemical is exhausted and
whereby the solution remains at a generally constar_t
concentration.
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5a
~nThile the invention will be described with respect
to a preferred embodiment ci rcui t configurati cn ar_d w_th
respect to particular circuit components used therei_~_,
it will be understood that the inventior_ is -!ot to be
cor_strued as limited in any manner by either such
circuit configurations or circuit components described
herein. Further, while the preferred e_mi~odiment of the
invention will be described in relation to a cleanina
product dispenser; and more specifically to a rinse
1~ additive solid product dispenser, it will be ur_derstood
that the scope of the invention is not to be limited by
the environment in which it is employed.
WO 94/27489 PCTIUS94/03498
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Other advantages and features which characterize the
invention are pointed out with particularity in the
claims annexed hereto and forming a part hereof.
However, for a better understanding of the invention,
its advantages and objectives obtained by its use,
reference should be had to the drawing which forms a
further part hereof and to the accompanying descriptive
matter, in which there is illustrated and described a
preferred embodiment to the invention.
Brief Description of the Drawings
Referring to the Drawings, wherein like numerals
represent like parts throughout the several views:
FIGURE 1 is a schematic block diagram of a
dispensing system of the type which employs the
principles of the present invention;
FIGURE 2 is a side elevational and exploded view of
the dispenser of Fig. 1 illustrating the location of the
sensor bracket 109, and with portions of hood 34 broken
away to illustrate the location of the aperture 100 for
the low product alarm 90 constructed according to the
principles of the present invention;
FIGURE 3 is a top plan view of the dispenser of Fig.
1 with the location of the low product alarm emitter
103, receiver 104, and light path 105 illustrated in
phantom;
FIGURE 4 is a front elevational view of the
dispenser 10 of Fig. 1 with portions broken away to
illustrate the location of the apertures 100, 101 for
the low product alarm 90;
FIGURE 5 is a functional block diagram illustrating
the various electrical components of the dispenser 10 of
Fig. 1 and the low product alarm 90; and
FIGURE 6 is a functional block diagram illustrating
the functional components of low product alarm 90
constructed in accordance with the present invention.
WO 94/27489 PCT/US94103498
2158027
Detailed Description of a Preferred Embodiment
As mentioned above, the principles of this invention
apply to the automatic detection of a low solid product
condition occurring in a dispenser of the type which
dilutes the solid product with a diluent to form a
predetermined concentration (or concentration range) of
liquid solution in a reservoir. The present invention
provides for perceptible indicia when such solid product
becomes low or otherwise reaches a predetermined level.
Therefore, variations in the liquid solution
concentration are minimized. A preferred application
for this invention is in the monitoring and detecting of
a low solid product condition in a wash chemical, and
more specifically a rinse additive environment. Such
application is typical of only one of the innumerable
types of applications in which the principles of the
present invention can be employed.
In order to better facilitate an understanding of
the present invention, a description of the low product
alarm will be deferred pending a discussion of a
preferred embodiment dispensing system.
DISPENSER 10
~teferring first to Fig. 1, a dispensing system is
indicated generally at 10. The dispensing system 10 has
a container or housing 11 with an upper storage portion
12 for holding a solid cleaning composition 65 (best
seen in Fig. 2). In the preferred embodiment, several
blocks may be placed within the upper storage portion
12. Fig. 2 illustrates two blocks 65a and 65b.
A door 13 extends across the upper end of the
storage portion 12 to provide access to the cavity
within the storage portion 12. At the lower end of the
container 11 is a collector portion 14. The lower end
of the collector portion 14 defines an outlet port 15
for passage therethrough of solution collected by
collector portion 14. Conduit 18 extends from the
WO 94!27489 PCT/US94I03498
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s
outlet port 15 to terminate at a position directly
overlying the reservoir 17. The outlet port 15 directs
the wash chemical solution downwardly as illustrated by
the arrow 82 by gravity. If the wash chemical is not
fed by gravity, a wash chemical solution pump (not
shown) could be provided in the outlet conduit 18.
A water supply inlet pipe 19 is connected to the
container 11 and is in communication therewith for
providing a source of water flow to a spray-forming
nozzle 20. The spray nozzle 20 directs water upwardly
as shown by the arrow 21 so as to impinge upon the solid
block of chemical 65, at which time the resulting liquid
cleaning solution descends through the collector portion
14 as shown by the arrow 22.
Control of the dispensing of the wash chemical
solution from the dispenser housing 11 is done by
controlling the flow of water to spray nozzle 20. This
may be done in a number of ways including mechanical
means such as hydraulic timer valves and electrical
means such as electrical switching in the control system
(not shown) of the utilization vehicle 23 (i.e., a ware
washing machine, washing machine, etc.). In the
preferred embodiment, the product 65 is a rinse additive
which is added to a water line at mixer 24.
Thereafter, conduit 16' carries the mixed water and
liquid product to utilization point 23. Also located at
mixer 23 is a pressure switch 102 (best seen in Fig. 5)
which monitors the pressure of the water being delivered
to utilization point 23. The switch 102 closes when
water is being delivered. Therefore, the dispenser 10
only operates when the liquid product is required at the
utilization point 23. Those skilled in the art will
appreciate that other time periods for operation may be
desired. The interconnection of the main functional
electrical components of dispenser 10 are more clearly
seen in Fig. 5.
WO 94127489 PCT/US94/03498
2158027 d
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The dissolved cleaning solution 25 is collected
within the reservoir 17 where it is available for use
when necessary by the utilization vehicle 23. Supply
conduit 16, 16' transports the cleaning solution to the
utilization vehicle 23, the supply conduit 16, 16'
having a pump 26 and other suitable flow control means.
In the preferred embodiment, the pump 26 is a
peristaltic pump. A pick-up tube 27 extends within the
reservoir 17 proximate the bottom wall 28 of the
reservoir 17 to withdraw the cleaning solution.
In the preferred embodiment, a float is positioned
within the reservoir 17 and operatively connected to a
float switch 32. The float switch 32 is operatively
connected to spray control means (such as solenoid valve
68) for controlling the flow of water to the nozzle 20,
in order to maintain a constant level of wash chemical
solution in the reservoir 17. When the level of wash
chemical solution in the reservoir 17 is below the
desired constant level, the float switch 32 is
electrically closed and the spray control means is
opened so that additional wash chemical solution 25 is
formed until the float 30 returns to its desired level.
Turning now to Fig. 2, an exploded view of the
dispenser assembly 10 is illustrated. The dispenser 10
is preferably configured so that it can be mounted upon
a wall near the utilization vehicle 23. The container
12 preferably has a hood 34, the upper portion of which
contains the housing 35 for the solid cleaning product
65 and the lower portion of which contains the flow
control assembly 41. The hood 34 is preferably made of
a stainless steel or molded plastic material.
Hood 34 preferably includes two apertures 100 and
101 formed therein which are sized and oriented through
the center line of the dispenser 10. The apertures 100,
101 are located at a predetermined height within
dispenser 10, wherein the low product alarm 90
(discussed in more detail below) detects a low product
21 5 8 0 2 7 . . ....
-.o
condition prv_or to actually running out of product.
?referably, the low product alarm 90 is enabled when the
so 1-id product droF>s to a level where the height of the
remaining product is eGUa1 to the height of one block 5S
remaining in the storage portion 12. Sensor
bracket/flange 109 is mounted within container 1 , and
is arranged and canfigured to place emitter 103 and
receiver 104 (discussed below) in operative position
elative to apertures 100 and 101 respectively. The
preferred orientation the sensors 103, 104 is proximate
apertures 100, 101 and forming a line starting with
emitter i03, continuir_g through the center of aperture
100, continuing through the center of aperture 101, and
ending at receive:.- 104. Those skilled in the art will
-~S appreciate that any number of other orientat;_cns of the
sensors may be provided in order to monitor tee~ amount
of solid product remaining in the c_spenser Ø
The size and Shape of the housing 35 confor_ns -~ri:_
the size and shape of the solid product capsu,_= ~S and
is preferably cylindrical. A =rant panel assembly 39 is
attachable to the wont portion of the hood 34. The
housing 3S is made o. a clear or translucent plastic
material, or contains a clear window, so as to enable an
operator to v=sually discern the level of sol;_d gash
2S composition c'S contained therein. 3dditionaliy, in the
preferred embodiment, the housing 3S must be constructed ,
of a material which does not interfere with the low
product alarm 90. Thus, clear or translucent plastic is
preferred. Fowever, those skilled in the art wi'_1
appreciate that other types of material might be used
which are opaaue. In that event, either additional
apertures or plastic inserts (i.e., translucent or clear
inserts) can be provided.
The door 13 is connected to the container 12 by
3S means of a hinge 33. In the preferred ernbodimera, there
is a magnet o'o on the cover i3 which controls the
opening and closing of a proximity switch 67. Opening
215802' . ~. w
of the cover 13 causes the proximity switch 67 to oven
and to turn off operation of the solenoid -ralve 6a which
controls water flow. This provides a safet~r featura to
pr ever_t the opera tor' s exposure to the wash chemi ca_ 55 .
Grates 36 and 37 are preferably positioned below the
solid detergent capsule 65, with the grate 36 having
relatively large ,apertures and supporting the solved wash
chemical 65. The grate 37 is positioned within the hood
34 and has relatively small apertures, on the order of
1.27 centimeters (1/2 inch) in diametar ir: the preferred
embodiment, so as to trap undesirable particles from
entering the wash chemical solution.
There is a seal 69 which serves as a d_vider between
the wetted wash chemical portion of the dispenser .0
above the seal 69 and the electror_ic flow control
assembly 41 below the seal 69. The sea. 69 could be a
J-cup, an 0-ring or any other su_table configurat=on.
The water enters the dispenser's water supply line
19 at water inlet point 71. The water line 19 is
provided with a vacuum breaker asse_Tnbly 70 which_
prevents backflow of the wash chemica_ _nto the wa-_er
supply 1 ine. The cleaning soluc_or_ t hen e:~its __.=c the
reservoir 17 at outlet port 40. The wash c~:em_cal
solution is withdrawn from reservoir 17 by mear_s of the
pick-up tube 27 and the pump 26. The cleaning so_~~tion
is then directed to the utilizatior_ vehicle 23 via
conduit 16, 16'.
At the lower end of the dispenser assembly 10 is the
reservoir 17. In the preferred embodiment, the
reservoir 17 is made of a plastic material such as
polymethylpentene or polypropylene, ar_d is formed of a
single, unitary piece. These types of plastic material
are transparent and have resistance to heat and
chemicals. Preferably, the reservoir 17 =s made of a
transparent or translucent material to allow the
CA 02158027 2002-12-17
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operator to see the amount of; wash chemical in the
reservoir 17.
The reservoir 17 includes a sump (not shown) within
the reservoir 17. A sump of the type utilized in
dispenser 10 is more fully discussed in issued U.S.
Patent 5,100,032,
Positioned within the reservoir 17 is a
pick-up tube 27. When cleaning solution is needed in
the utilization vehicle 23, the pump 26 is energized and
cleaning solution is withdrawn from the reservoir 17 via
the pick-up tube 27. The bottom of the pick-up tube 27
is positioned slightly above the bottom of the reservoir
17, preferably approximately 0.3175 centimeter (1/8
inch). The pick-up tube 27 is preferably made of a
polypropelene material. The pick-up tube 27 contains a
suitable flow indicator 80 such as one having a ball
float 81, to enable the operator to visually monitor
flow of the wash chemical from the reservoir 17.
The dispenser outlet 40 is positioned directly above
the sump, so that the cleaning solution dispenses into
the sump. It then overflows into the main reservoir 17.
In the preferred embodiment, each dispensing cycle
produces approximately 70 milliliters of liquid. As
used herein, the term "dispensing cycle" refers to a
single activation of the float switch 32. The switch
may be activated more than once during a single cleaning
cycle of the utilization vehicle 23.
In the preferred embodiment, the volume of the
reservoir 17 is enough for approximately five to ten
cycles in the utilization vehicle 23. By making up a
quantity of chemical solution 25 and storing it in the
reservoir I7, the solution is immediately available
whenever the utilization vehicle 23 requires it.
LOW PRODUCT ALARM 90
Turning now to Fig. 5, a functional block diagram of
the electrical elements of dispenser 10 and low product
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alarm 90 is illustrated. In the preferred embodiment,
the low product alarm 90 is used in a dispenser for a
liquid rinse additive. Accordingly, the rinse additive
is required only when hot rinse water is being used.
Thus, as noted above, pressure switch 102 only closes
when the utilization vehicle 23 is using rinse water
(i.e., hot rinse water is being delivered).
Switch 67 is a cover safety switch which avoids
turning on the solenoid valve 68 as discussed above.
Also in series with switch 67 and valve 68 is float
switch 32. Those skilled in the art will appreciate
that solenoid valve 68 only turns on (i.e., opens to
allow spray nozzle 20 to spray block 65) when pressure
switch 102 indicates that water is being used at the
utilization vehicle 23, the cover switch 67 is closed,
and the float switch 32 indicates that additional
solution 25 is required.
On a parallel circuit, but also in series with
pressure switch 102, is the speed controller 108 for
controlling the speed of the motor for pump 26. In the
preferred-embodiment, the controller 108 provides a
source for a regulated voltage. Therefore, the low
product alarm 90 is connected at this location. Those
skilled in the art will appreciate that any other
regulated voltage source may be provided in order to
power low product alarm 90. Also, while not
specifically detailed in Figs. 5 and 6, it will be
understood that the functional blocks, and other
devices, are properly connected to appropriate bias and
reference supplies so as to operate in their intended
manner.
Next referring to Fig. 6, a more detailed functional
block diagram of the electrical components of low
product alarm 90 is illustrated. First, emitter 103
generates an infrared beam 105. The beam 105 preferably
travels through the aperture 100 and through the
transparent housing 35. If no opaque solid product 65
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14
blocks the light 105 along path 105' (illustrated in
Fig. 4, where solid block 65b lies below the light path
line 105'), then the beam 105 continues through the
other side of housing 35, through aperture 101 and
strikes the operative light sensitive surface of
receiver 104.
The receiver 104 is normally off in operation (i.e.,
it acts as a switch which turns on when a beam is
incident on the operative surface of the receiver 104).
However, when the beam 105 strikes the receiver 104,
then it turns on and provides a voltage to operate the
perceptible indicia means comprised of horn 106 and
light 107. When solid block 65 lies within path 105',
then receiver 104 remains off. Thus, receiver 104 acts
as a means for determining whether a predetermined
amount of solid block 65 is present.
The perceptible indicia are preferably located such
that they can be heard and seen respectively by users of
dispenser 10. Thus, light 107 is preferably located on
the front of dispenser 10 and the horn 106 is placed
through the bottom or side wall of dispenser 10.
Alternatively, the perceptible indicia may be located in
a remote location from dispenser 10 if the location is
more perceptible to a user. Also, a variable resistor
(not shown) may be placed in line with horn 106 to vary
the volume of the horn 106.
When the low product alarm 90 detects a low solid
block 65 condition, the perceptible indicia means are
turned on to alert a user that the solid block 65
requires replenishment. This maintains the solution 25
at a more uniform concentration level and maximizes the
efficiency of the chemical. By directly monitoring the
height of solid block 65 within the dispenser 10, a
simple and effective method of monitoring the
concentration level of solution 25 is achieved.
It will be appreciated by those skilled in the art
that the low product alarm 90 may be connected to a
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reference voltage supply in at least one of two optional
configurations. First, the low product alarm 90 may be
connected so as to continuously monitor the block 65
and/or continuously trigger an alarm in the event of a
5 low product condition. Second, the low product alarm
may be connected so as to only monitor the block 65
and/or trigger an alarm when pressure switch 102 is
closed.
In the preferred embodiment, emitter 103 and
10 receiver 104 are manufactured by Banner Engineering
Corporation of Minneapolis, Minnesota and have the
designation SE61E and SE 61R respectively. Those
skilled in the art will appreciate that other emitters
and receivers might be used. Factors used in selecting
15 the sensors include operation in both light and dark
environments, temperature and chemical resistance,
voltage fluctuation rejection, and ability to operate
through housing 35 even when contaminated with elements
of solid block 65. In the preferred embodiment, horn
106 is an alarm manufactured by Mallory and having the
designation SONALERT SC628.
Even though numerous characteristics and advantages
of the invention have been set forth in the foregoing
description, together with the details of the structure
and function of the invention, the disclosure is
illustrative only, and changes may be made in detail,
especially in matters of shape, size, and arrangement of
parts, within the principles of the invention, to the
full extent indicated by the broad, general meaning of
the appended claims.
